Basic Electric Fetal Heart Monitoring
What Does Fetal Monitoring Tell Us - ANS-To Confirm Fetal well-being
- Fetal oxygenation
- Acid-base status of the fetus
- Ability of the CNS to regulate FHR
- Why monitor? Prevention of hypoxia/asphyxia
Consequences of Inutero Hypoxia/Asphyxia - ANS-- Cerebral Palsy
- Mental Retardation
- Epilepsy
- RDS: Respiratory Distress Syndrome
- Renal Damage
- NEC (Necrotizing Enterocolitis): GI not perfused with O2
- Chronic Brain Impairment
External Monitoring:
Device Placement
Toco - ANS-- Toco transducer which senses uterine activity
- Placed on top of stomach at the fundus
- this area has most contractility
- plug into the UA (uterine activity)
- round but not smooth in appearance
External Monitoring:
Device Placement
Ultrasound - ANS-- Ultrasound device is lower on the stomach and senses the fetal
heart beat
- only the round ultrasound transducer which detects the heart beat gets the ultrasound
jelly
- round and smooth in appearance
Internal Monitoring:
Fetal Scalp Electrode (FSE) - ANS-- Internal fetal heart monitor
- used b/c the fetus can move away from the ultrasound
- small device inserted through cervix and attached to fetal scalp, can leave a small
mark on head of infant
Internal Monitoring:
, Intrauterine Pressure Catheter (IUPC) - ANS-- Internal contraction monitor (measures
strength of contraction)
- used when the bag has ruptured
- must be 3cm
- small device inserted through cervix but not attached to fetus
- FSE and IUCP can be used independently of each other
IUCP & Contraction Measurements - ANS-- The intensity of contractions can only be
measured objectively with an IUPC in place
- Without it, must assess strength of contraction subjectively by palpating the fundus
during contraction
- If the fundus tone feels like:
-- Tip of nose = mild contraction
-- Chin = moderate contraction
-- Forehead = strong contraction
- Toco measures contractions but not their strength
Fetal Heart Monitoring - ANS-- looks like an EKG strip
- top line represents the fetal heart rate
- bottom line represents the contractions
- vertical line on paper shows beats per minute (bpm)
- length of each box is 10 seconds
Counting Contractions - ANS-- Duration: From beginning to end of one contraction
(length of contraction)
- Frequency: Beginning of one contraction to the beginning of the next contraction
-- chart as "contracting q5min"
-- fetus is not perfused during contraction
Uterine Perfusion During Contractions - ANS-- Strong contractions cut off blood flow
- peak of contraction on the strip is called the ACME of contraction
- hill shape on strip is acceleration, U shape on strip is deceleration
Three Important Components of the Fetal Heart Monitor Strip - ANS-1) Baseline Heart
Rate
- Is it normal, bradycardia below 110, tachycardia above 160?
2) Variability
- Is it present or absent?
- r/t tracing on strip
3) Periodic Changes
What Does Fetal Monitoring Tell Us - ANS-To Confirm Fetal well-being
- Fetal oxygenation
- Acid-base status of the fetus
- Ability of the CNS to regulate FHR
- Why monitor? Prevention of hypoxia/asphyxia
Consequences of Inutero Hypoxia/Asphyxia - ANS-- Cerebral Palsy
- Mental Retardation
- Epilepsy
- RDS: Respiratory Distress Syndrome
- Renal Damage
- NEC (Necrotizing Enterocolitis): GI not perfused with O2
- Chronic Brain Impairment
External Monitoring:
Device Placement
Toco - ANS-- Toco transducer which senses uterine activity
- Placed on top of stomach at the fundus
- this area has most contractility
- plug into the UA (uterine activity)
- round but not smooth in appearance
External Monitoring:
Device Placement
Ultrasound - ANS-- Ultrasound device is lower on the stomach and senses the fetal
heart beat
- only the round ultrasound transducer which detects the heart beat gets the ultrasound
jelly
- round and smooth in appearance
Internal Monitoring:
Fetal Scalp Electrode (FSE) - ANS-- Internal fetal heart monitor
- used b/c the fetus can move away from the ultrasound
- small device inserted through cervix and attached to fetal scalp, can leave a small
mark on head of infant
Internal Monitoring:
, Intrauterine Pressure Catheter (IUPC) - ANS-- Internal contraction monitor (measures
strength of contraction)
- used when the bag has ruptured
- must be 3cm
- small device inserted through cervix but not attached to fetus
- FSE and IUCP can be used independently of each other
IUCP & Contraction Measurements - ANS-- The intensity of contractions can only be
measured objectively with an IUPC in place
- Without it, must assess strength of contraction subjectively by palpating the fundus
during contraction
- If the fundus tone feels like:
-- Tip of nose = mild contraction
-- Chin = moderate contraction
-- Forehead = strong contraction
- Toco measures contractions but not their strength
Fetal Heart Monitoring - ANS-- looks like an EKG strip
- top line represents the fetal heart rate
- bottom line represents the contractions
- vertical line on paper shows beats per minute (bpm)
- length of each box is 10 seconds
Counting Contractions - ANS-- Duration: From beginning to end of one contraction
(length of contraction)
- Frequency: Beginning of one contraction to the beginning of the next contraction
-- chart as "contracting q5min"
-- fetus is not perfused during contraction
Uterine Perfusion During Contractions - ANS-- Strong contractions cut off blood flow
- peak of contraction on the strip is called the ACME of contraction
- hill shape on strip is acceleration, U shape on strip is deceleration
Three Important Components of the Fetal Heart Monitor Strip - ANS-1) Baseline Heart
Rate
- Is it normal, bradycardia below 110, tachycardia above 160?
2) Variability
- Is it present or absent?
- r/t tracing on strip
3) Periodic Changes
